Such devices are generally known. They are used to form products such as containers for coffee milk, yoghurt, salads and numerous other products by a blow-moulding process. Used as a starting point here is a thin layer of material which is deformable when heated and which is pushed fixedly into the cavity by means of compressed air, or pressurized air, is there cooled, whereby the shape is retained, and the completed product is then transported away.
The fact that product which is to a certain degree form-retaining must be removed from the mould imposes limitations in the prior art on the shape of the product.